Panel Structure For Mounting Electrical Components To Provide Front Access Thereto

Abstract

A panel mounting unit for a replaceable electrical component, e.g. a lamp or fuse link, has three main parts: a housing, to be mounted on the panel, a component holder which fits into the housing, and a latching mechanism serving to lock the holder and housing together when the holder is initially pushed into the housing, the mechanism operating to free the holder when the latter is subsequently pushed inwardly.

Description

This invention relates to panel mountings for electrical components which periodically need replacing, such as indicator lamps and fuse links.

An aim of this invention is the provision of a panel mounting suited to be fitted flush with the front surface of a panel, i.e., without the mounting protruding therefrom, and which is of a construction allowing access to the component from the front of the panel when replacement becomes necessary.

According to the present invention, there is provided a panel mounting for an electrical component that periodically needs replacing, the mounting comprising a housing to be secured to a panel, a holder which is movable into and out of the housing for accommodating the electrical component, a latching mechanism which locks the holder within the housing upon the holder being pushed into the housing, the latching mechanism being arranged to release the holder when the holder is pressed inwardly from the position it assumes when locked in the housing, and biasing means for urging the released holder outwardly toward a position allowing access to the component for replacement thereof. In use, the mounting is preferably so fitted to the panel that the front of the holder, when locked in the housing lies flush with the front surface of the panel. To release the holder, its front surface is depressed below the front of the panel, after which the biasing means will act to urge the holder outwardly so that access may be had to the component. It may be arranged that the holder is ejected wholly from the housing by the biasing means. In a preferred embodiment, however, the mounting includes means resisting ejection of the released holder from the housing so that, in the position to which it is urged by the biasing means, the holder protrudes only parly from the housing, enabling the holder to be grasped and pulled free from the said resisting means and out of the housing. It will be understood that in normal circumstances, the holder lies flush with the panel: it only protrudes therefrom when unlocked for replacement of the electrical component.

The latching mechanism is in two parts, carried by the holder and the housing respectively, the parts preferably consisting of an element including a toothed abutment and a claw-ended panel which interengage, and are held interengaged by the said biasing means, for locking the holder, the panel being spring-pressed towards a position in which it is freed from the abutment to release the holder but movement thereof towards the freed position being arrested by the tooth until the holder is pressed inwardly against the said biasing means, whereupon the claw disengages from the abutment and rides over the tooth to its freed position under the action of the spring pressing the panel. Preferably, the panel is pivotally mounted inside the housing and the toothed abutment element is carried by the holder, and conveniently the toothed abutment element has the form of an elevation on the holder.

In the preferred embodiment, means are provided for preventing the panel entering the said freed position without first moving into locking interengagement with the abutment when the holder is pushed into the housing. Conveniently, the said means includes two further teeth adjacent the abutment which present an obstacle to movements of the panel, which can only be surmounted and passed by the panel if the panel moves towards and into locking engagement with the abutment.

The holder in the preferred embodiment is held captive to the housing, for example by a slideable hinge link. Spring-loaded plungers provide electrical connections between the electrical component in the holder and associated terminals in the housing and one, or more, of these plungers may serve as the said biasing means.

The invention will now be described by way of example with reference to the accompanying drawings, in which:

FIG. 1 is a perspective view of a panel containing a panel mounting embodying the present invention,

FIG. 2 illustrates another perspective view of the mounting, shown opened for replacement of the electrical component therein,

FIG. 3 is a cross-section through the panel mounting, and

FIG. 4 is a side elevation of the panel mounting.

The illustrated panel mounting 10 is an indicator light suitable for control/display panels in computers, ships control centres, electricity supply centres and the like. The mounting 10 in this instance includes a pair of miniature lamps 11, the components which periodically need replacing. The mounting 10 is intended to be mounted in the panel 12 with its front normally flush with the face 13 of the panel 12, as illustrated in FIG. 4. The mounting 10 is constructed for easy replacement of the lamps 11 without the need for access to the rear of the panel 12 and without the need for removing the mounting 10 from the panel 12. For this purpose, the mounting can be opened, as illustrated in FIG. 2 and as will be described.

The mounting 1o consists of a housing 14, provided with flanged plates 15 for securing the housing to the panel 12, and a holder 16 which is arranged to grip the lamps 11. The panel 12 is apertured as shown at 17 for accommodating the holder 16, which fits inside the housing 14 and is movable therein. The housing 14 has sheet metal walls, is open at one end to receive the holder 16 and is closed at its other end by an insulating wall 18 provided with three terminals 19. Three spring-loaded plungers 21, 22, 23 are provided to establish electrical connections between the terminals and the lamps 11 when the holder 16 is in its normal position within the housing 14 illustrated in FIG. 3, the centre plunger 22 making contact with both lamps. The spring-loaded plungers 21, 22 and 23 act to urge the holder 16 outwardly from the housing 14 but outward movement is prevented by a latching mechanism 25 seen in FIG. 4.

The latching mechanism 25 is in two parts, of which one part is a pawl 26 pivotally mounted to an end wall of the housing 14. The other part includes a toothed abutment element 28 formed as an elevation on the corresponding end wall of the holder 16. The pawl 26 is pressed by a spring 29 anti-clockwise about its pivot, see FIG. 4, towards a freed position in which it is disengaged from the element 28. At its end remote from the pivot, the pawl has a claw 30 which co-operates with the toothed abutment 28 element to lock the holder 16 in the housing 14. The elevated toothed abutment element 28 forms a ledge 31 which extends transversely across the holder 16, and when the claw 30 is engaged with the ledge 31, as seen in FIG. 4, the holder 16 is held locked in the housing 14, in its normal position. At its left-hand end, the ledge 31 terminates in a tooth 32 against which the claw 30 is pressed by the spring 29, the tooth 32 preventing the claw 30 from slipping sideways from the ledge 31.

The toothed abutment element 28 has an inclined edge 33 leading towards the ledge 31 and a second tooth 34 is located at the junction of the ledge 31 and the inclined edge 33. A third tooth 35 is formed on the holder 16, and is spaced from the ledge 31. The two teeth 34 and 35 serve as an obstacle to movement of the pawl 26, preventing the panel leaving the inclined edge 33 and moving towards its freed position without first moving into locking engagement with the ledge 31.

The latching mechanism 25 operates as follows. When the holder 16 is moved into the housing 14, the claw 30 of the pawl 26 engages the lower, left-hand end of the inclined edge 33. Continued movement of the holder 16 into the housing 14 causes the edge 33 to cam the pawl 26 clockwise, loading the spring 29 and causes compression of the springs of the spring-loaded plungers 21 to 23. When the claw of the pawl 26 reaches and passes the top, right-hand end of the inclined edge 33, the spring 29 urges it anticlockwise past the tooth 34, and it moves sideways into engagement with the tooth 35. The two teeth 34 and 35 coact to prevent the claw 30 leaving the inclined edge 33 and directly moving towards its freed position without first engaging the ledge 31. Once the claw has engaged the tooth 35, as soon as the holder 16 is released the spring-loaded plungers push the holder 16 outwardly and the claw 30 is freed from the tooth 35, engages the ledge 31 and moves into abutment with the tooth 32. In this position, the holder 16 is locked in the housing 14.

The holder 16 is unlocked, when replacement of the lamps 11 is required, by pressing the holder 16 inwardly against the bias of the spring-loaded plungers 21 to 23. This causes the tooth 32 to move downwardly and as it does so the spring-pressed pawl 26 rides over the tooth 32 into its said freed position to the left of the tooth 32. Once released, the spring-loaded plungers 21 to 23 urge the holder outwardly to a position allowing replacement of the lamps 11. It is only necessary for one plunger, say the centre plunger 22 to be effective as the biasing means which actually urge the holder 16 into this position.

The mounting 10 is provided with means resisting ejection of the holder 16 from the housing 14. The resistance is provided by a ramp 40 on the holder 16 which engages the claw 30 when the holder moves outwardly. The ramp 40 limits the outward movement such that the holder 16 is retained protruding only partly from the housing, see FIG. 1. It is arranged that the pawl 26 is free to move slightly away from the holder 16 so that when the protruding holder 16 is grasped and pulled, its ramp 40 can be pulled free from the claw 30 to enable the holder to be removed from the housing 14. The ramp 40 forms a step at the lower, left-hand end of the inclined edge 33, the step being a continuation of the inclined edge 33. Provision of the step ensures that the pawl 26 rides along the inclined edge when the holder 16 is pushed into the housing 14.

The holder 16 is held captive to the housing 14 by a hinge link 41 one end of which is slideably received in a track 42 formed in the housing. The other end of the link 41 is pivotally connected with the holder 16. The front face of the holder 16 has a window or screen of coloured translucent plastics material which is releasably held in the holder to allow different coloured screens to be installed.

The housing 14 is provided with a number of apertures or slots 44 for assisting dissipation of heat generated in use by the lamps 11.

Although the panel mounting 10 described above has two lamps 11 and three associated terminals 19 and plungers 21 to 23, it will be appreciated that the holder may be arranged to accommodate only one lamp, such as a neon tube. Also, it may be arranged to accommodate a conventional fuse link cartridge. If the panel mounting is to be used with a single lamp or a fuse link, then only two terminals and plungers are needed.

Claims

We claim

1. A panel mounting for receiving an electrical component and for connecting it to circuitry behind the panel, the mounting allowing replacement of said component from the front of said panel, and said mounting comprising:

a housing for attachment to a panel;

a holder for accommodating said component, said holder being movable into and out of said housing;

biasing means within said housing for urging said holder outwardly therefrom whereby access can be gained to said holder for replacement of said component;

a latching mechanism comprising a latch member and a latch holding means, which coact to retain said holder in a locked position within said housing, said mechanism being operable when said holder is pressed further inwardly from its locked position to release said latch member from said latch holding means whereby said holder is unlocked enabling ejection thereof from said housing;

said latch member being a pawl which is pivotally mounted alongside an inner wall of said housing;

said latch holding means is an elevation on the outer surface of said holder, said elevation defining a toothed abutment surface;

said pawl having a claw end engageable with said toothed abutment surface for locking said holder, said biasing means urging said claw end and said toothed abutment element to interengage;

spring means for moving said latch member towards a position in which it is freed from said toothed abutment element to release said holder;

a tooth on said toothed abutment element preventing free movement of said latch member until said holder is moved further inwardly from its locked position against said biasing means, whereupon said claw end can ride over said tooth and reach its freed position under the action of said spring means.

2. A mounting according to claim 1, including means for preventing complete ejection of said released holder from said housing by said biasing means, whereby said holder is permitted to protrude only parly from said housing.

3. A mounting according to claim 1, wherein said elevation defining said toothed abutment element includes an inclined surface leading towards its abutment to deflect said latch member away from its freed position, whereby said spring means is loaded as said holder is pushed into said housing.

4. A mounting according to claim 3, and further including means for preventing said latch member from leaving said inclined surface and entering said freed position, said means presenting an obstacle to movement of said latch member, whereby said latch member can only surmount said obstacle by moving towards and into locking engagement with said toothed abutment element.

5. A mounting according to claim 4, wherein said obstacle comprises a first tooth located on said toothed abutment element adjacent the abutment-end of said inclined surface and a second tooth mounted on said holder adjacent said toothed abutment element.

6. A mounting according to claim 2, including a ramp located adjacent said toothed abutment element for engagement with said claw end to prevent complete ejection of said holder from said housing after release thereof whereby said holder is caused to protrude only partly from said housing.

7. A mounting according to claim 6, wherein the end of said ramp remote from the abutment-end of said toothed abutment element forms a step located at the end of said inclined surface remote from the abutment-end thereof.

8. A mounting according to claim 1, and further including means for holding said holder captive to said housing.

9. A mounting according to claim 8, wherein said captive holding means includes a slideable hinge link having one end pivotally connected to said holder and its other end slideably received in a track provided in said housing.

10. A mounting according to claim 1, wherein said biasing means includes at least one spring-loaded plunger, and said housing includes at least one electrical terminal for connection to an external circuit, said spring-loaded plunger serving as a spring-loaded electrical contact between said electrical component and said terminal.

11. A mounting according to claim 1, in the form of a panel indicator light, said holder accommodating at least one lamp and having a coloured, translucent screen mounted in front of the lamp.